Shale shakers with selective series/parallel flow path conversion

ABSTRACT

Methods and systems are disclosed employing a shale shaker for processing a mixture of drilling fluid and solids with multiple screen assemblies and conversion apparatus for switching flow to the screen assemblies between series flow and parallel flow; and in one aspect, a screen or screens for screening lost circulation material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 12/490,492, filed Jun. 24, 2009, which was a continuation-in-part of U.S.application Ser. No. 12/287,709, filed on Oct. 10, 2008, now U.S. Pat.No. 8,113,356, incorporated by reference herein for all it discloses.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to drilling fluid processing systems;shale shakers; to methods for using these things; and, in certainparticular aspects, to shale shakers with structure for convertingshaker fluid flow paths from series to parallel, and vice versa.

2. Description of the Related Art

In the oil and gas industries, shale shakers use screens to treatdrilling fluid contaminated with undesirable solids. Typically suchapparatuses have a basket, deck, or other screen holding or mountingstructure mounted in or over a receiving receptacle or tank andvibrating apparatus for vibrating one or more screens. Material to betreated is introduced to the screen(s) either by flowing it directlyonto the screen(s) or by flowing it into a container, tank, or “possumbelly” from which it then flows to the screen(s). Often, the screen orscreens used to treat material is sealed in place on a screen deck, in ascreen basket, or on screen mounting structure.

In the past it has been common to use multiple screens at multiplelevels in a shale shaker to process drilling fluid, e.g., screens atone, two or three levels.

“Lost circulation” of drilling fluid occurs when, in drilling awellbore, the circulation of drilling fluid to and then away from thedrill bit ceases due to the porosity of the formation and/or due tofracturing of the formation through which the wellbore is being drilled.When lost circulation occurs, drilling fluid is pumped into thefractured formation rather than being returned to the surface. Oftencirculation is lost at some specific depth where the formation is“weak”, and that the fracture extends horizontally away from theborehole. Expressions used to describe rocks that are susceptible tolost returns include terms like vugular limestone, unconsolidated sand,“rotten” shale, and the like.

A wide variety of “lost circulation materials” (“LCM”) have been pumpedinto wellbores to fill or seal off a porous formation or to fill or sealoff a wellbore fracture so that a proper route for drilling fluidcirculation is re-established. Often lost circulation materials aregenerally divided into fibers, flakes, granules, and mixtures.

Often it is also desirable to recover and retain the lost circulationmaterial in the drilling mud system during continuous circulation.Screening the drilling mud for removal of undesired particulate mattercan also result in removal of the lost circulation material and,therefore, require continuous introduction of new lost circulationmaterial to the drilling mud downstream of the mud screening operation.

The addition of lost circulation material compounds the separatingproblems because it, like the drilling fluid, is preferably cleaned andrecirculated. Exiting the well is the drilling fluid of small size, thelost circulation material of a large size, and the undesirable materialof a size therebetween, with the largest and smallest of the materials,and/or materials larger than the lost circulation material, to bere-circulated. One proposed solution to this separation problem is aconventional two step screening process as shown in U.S. Pat. No.4,116,288. There the exiting mixture of drilling fluid, lost circulationmaterial and undesirable material is first subjected to a coarsescreening to separate the lost circulation material from the drillingfluid and undesirable material which drops to a second finer screentherebelow to separate the drilling fluid from the undesirable material.The drilling fluid and lost circulation material are then reunited forrecirculation into the well. This system is susceptible to heightrestrictions and fine screen problems. The lost circulation material canbe coated with undesirable material which will not go through a firstscreen, moves over and exits off of the top side of the first screen,and is circulated back into a well.

There are a variety of known drilling fluid processing systems, shaleshakers, and methods for recovery of lost circulation material;including, for example, but not limited to, those in U.S. Pat. Nos.6,868,972; 6,669,027; 6,662,952; 6,352,159; 6,510,947; 5,861,362;5,392,925; 5,229,018; 4,696,353; 4,459,207; 4,495,065; 4,446,022;4,306,974; 4,319,991; and 4,116,288 (all said patents incorporated byreference herein for all purposes).

In certain prior systems, problems have been encountered with systemsfor screening out lost circulation material when undesirable material ofthe same size is also screened out.

BRIEF SUMMARY OF THE INVENTION

The present invention discloses, in certain aspects, methods and systemsfor processing drilling fluid to recover components thereof and, in oneparticular aspect to multi-screen shale shakers in which fluid flowpaths can be selectively changed from series to parallel, and viceversa.

In certain particular aspects, such methods and systems employs a novelshale shaker according to the present invention with screening apparatusincluding multiple screens and conversion apparatus for changing a firstseparation mode from material flowing from one screen to another inseries to a second separation made in which fluid flows to multiplescreens in parallel.

The present invention discloses, in certain aspects, a system forprocessing a mixture of drilling fluid and solid material to separate atleast one component of the mixture by size from the mixture, the systemincluding: a vibratable basket for receiving an input flow of drillingfluid with solids therein; a plurality of spaced-apart screen assembliesincluding a first screen assembly and a second screen assemblypositioned below the first screen assembly; the screen assembliesmounted in the vibratable basket and vibratable therewith; conversionapparatus associated with the screen assemblies for selectivelycontrolling the input flow to select one of series flow and parallelflow to the screen assemblies; drilling fluid flowable through the firstscreen assembly; and drilling fluid flowable through the second screenassembly and flowable down therefrom.

A vibratory separator or shale shaker, in one embodiment according tothe present invention has a screen or screens at separate levels asdescribed herein according to the present invention. In one particularaspect, two lowermost screens receive flow from a higher screen.Conversion apparatus permits this flow to be selectively changed fromparallel to series, or vice-versa. The present invention, in certainembodiments, includes a vibratory separator or shale shaker with a baseor frame; a “basket” or screen mounting apparatus on or in the base orframe; multiple screens at different, spaced-apart distinct levelsaccording to the present invention; vibrating apparatus; mode conversionapparatus; and a collection tank or receptacle. Such a shale shaker cantreat drilling fluid with solids therein, e.g. cuttings, debris, etc.;and drilling fluid with lost circulation material therein.

The present invention discloses, in certain aspects, a conversionapparatus for a system for processing a mixture of drilling fluid andsolid material to separate at least one component of the mixture fromthe mixture, the system including a vibratable basket for receiving aninput flow of drilling fluid with solids therein, a plurality ofspaced-apart screen assemblies including a first screen assembly and asecond screen assembly positioned below the first screen assembly, thescreen assemblies mounted in the vibratable basket and vibratabletherewith, drilling fluid flowable through the first screen assembly andthe second screen assembly down therefrom, the conversion apparatusassociated with the screen assemblies for selectively controlling theinput flow to select one of series flow and parallel flow, theconversion apparatus including: a body, a first flow channel through thebody for effecting system parallel flow to the screen assemblies, and asecond flow channel through the body for effecting system series flow tothe screen assemblies.

In certain particular aspects, an insert between screens is a movablegate structure between screens provides the mode conversion feature. Inother aspects inserts adjacent screens, appropriate flow channeling, andappropriately located flowback barriers provide this mode conversionfeature.

The present invention discloses, in certain aspects, a method fortreating a flow of drilling fluid with solids, the method includingintroducing the flow of drilling fluid with solids to a system forseparating at least one component from the flow, the system as anyherein according to the present invention, the method further includingselecting one of a system series flow to the screen assemblies or asystem parallel flow to the screen assemblies using a conversionapparatus, flowing drilling fluid with solids to the screen assemblies,and screening the flow to each screening assembly.

The present invention discloses, in certain aspects, methods and systemsfor processing drilling fluid to recover components thereof and, in oneparticular aspect for separating lost circulation material (or lostcirculation material along with solids of similar size) from useddrilling fluid. In certain aspects, the separated lost circulationmaterial is recovered and used.

In certain particular aspects, such methods and systems employs a novelshale shaker according to the present invention with screening apparatusbelow an initial scalper screen apparatus for separating lostcirculation material (and/or material of similar size) from useddrilling fluid.

A vibratory separator or shale shaker, in one embodiment according tothe present invention has a screen or screens at separate levels asdescribed herein according to the present invention. In one particularaspect, two lowermost screens can receive flow from a higher screen inparallel or in series. The present invention, in certain embodiments,includes a vibratory separator or shale shaker with a base or frame; a“basket” or screen mounting apparatus on or in the base or frame;screens at three or four different, spaced-apart distinct levelsaccording to the present invention; vibrating apparatus; and acollection tank or receptacle. Such a shale shaker can treat drillingfluid contaminated with solids, e.g. cuttings, debris, etc.; anddrilling fluid with lost circulation material (and/or material ofsimilar size) therein. Such a shale shaker, in certain aspects, providesa separate exit stream from a second screening level which is primarilylost circulation material (and/or material of similar size).

Accordingly, the present invention includes features and advantageswhich are believed to enable it to advance the processing of drillingfluid with lost circulation material (and/or material of similar size)therein. Characteristics and advantages of the present inventiondescribed above and additional features and benefits will be readilyapparent to those skilled in the art upon consideration of the followingdetailed description of preferred embodiments and referring to theaccompanying drawings.

Certain embodiments of this invention are not limited to any particularindividual feature disclosed here, but include combinations of themdistinguished from the prior art in their structures, functions, and/orresults achieved. Features of the invention have been broadly describedso that the detailed descriptions that follow may be better understood,and in order that the contributions of this invention to the arts may bebetter appreciated. There are, of course, additional aspects of theinvention described below and which may be included in the subjectmatter of the claims to this invention. Those skilled in the art whohave the benefit of this invention, its teachings, and suggestions willappreciate that the conceptions of this disclosure may be used as acreative basis for designing other structures, methods and systems forcarrying out and practicing the present invention. The claims of thisinvention are to be read to include any legally equivalent devices ormethods which do not depart from the spirit and scope of the presentinvention.

In addition to the specific objects stated below for at least certainpreferred embodiments of the invention, other objects and purposes willbe readily apparent to one of skill in this art who has the benefit ofthis invention's teachings and disclosures.

It is, therefore, an object of at least certain preferred embodiments ofthe present invention to provide the embodiments and aspects listedabove and:

New, useful, unique, efficient, non-obvious drilling fluid processingsystems; shale shakers; and methods of the use of these systems andshakers;

Such shale shakers with screens at multiple levels and mode conversionapparatus so that material is screenable by multiple screens in seriesor in parallel selectively as desired;

Such shale shakers with screens at four levels according to the presentinvention with the last two screens operating in series or in parallel;and

New, useful, unique, efficient, non-obvious drilling fluid processingsystems and shale shakers; and methods of their use for separating andrecovering lost circulation material (and/or material of similar size)from spent drilling fluid.

The present invention recognizes and addresses the problems and needs inthis area and provides a solution to those problems and a satisfactorymeeting of those needs in its various possible embodiments andequivalents thereof. To one of skill in this art who has the benefits ofthis invention's realizations, teachings, disclosures, and suggestions,other purposes and advantages will be appreciated from the followingdescription of certain preferred embodiments, given for the purpose ofdisclosure, when taken in conjunction with the accompanying drawings.The detail in these descriptions is not intended to thwart this patent'sobject to claim this invention no matter how others may later attempt todisguise it by variations in form, changes, or additions of furtherimprovements.

The Abstract that is part hereof is neither intended to define theinvention, which is done by the claims, nor is it intended to belimiting of the scope of the invention or of the claims in any way.

It will be understood that the various embodiments of the presentinvention may include one, some, or all of the disclosed, described,and/or enumerated improvements and/or technical advantages and/orelements in claims to this invention.

Certain aspects, certain embodiments, and certain preferable features ofthe invention are set out herein. Any combination of aspects or featuresshown in any aspect or embodiment can be used except where such aspectsor features are mutually exclusive.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of embodiments of the invention brieflysummarized above may be had by references to the embodiments which areshown in the drawings which form a part of this specification. Thesedrawings illustrate certain preferred embodiments and are not to be usedto improperly limit the scope of the invention which may have otherequally effective or legally equivalent embodiments.

FIG. 1 is a schematic view of a system according to the presentinvention.

FIG. 1A is a perspective view of a shale shaker according to the presentinvention.

FIG. 2A is a side view, partially in cross-section, of a shale shakeraccording to the present invention.

FIG. 2B is a cross-sectional view of the screens and related structureof the shale shaker of FIG. 2A.

FIG. 2C is a cross-sectional view of a shale shaker according to thepresent invention.

FIG. 3A is a side cutaway view of a shale shaker according to thepresent invention.

FIG. 3B is a side cutaway view of a shale shaker according to thepresent invention.

FIG. 4A is a perspective exploded view of a system according to thepresent invention.

FIG. 4B is a schematic side view of the system of FIG. 4A.

FIG. 5A′ is a perspective exploded view of a system according to thepresent invention.

FIG. 5A″ is a continuation of FIG. 5A′.

FIG. 5B is a schematic side view of the system of FIG. 5A.

FIG. 6A is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 6B is a side cross-sectional view of the shale shaker of FIG. 6A.

FIG. 6C is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 6D is a side cross-sectional view of the shale shaker of FIG. 6C.

FIG. 6E is a perspective view of a diverter according to the presentinvention.

FIG. 6F is a front view of the shaker of FIG. 6A.

FIG. 6G is a cross-section view of the diverter of FIG. 6E in the shakerof FIG. 6A.

FIG. 7A is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 7B is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 7C is a perspective view of a flow barrier according to the presentinvention.

FIG. 7D is a perspective view of a flow barrier according to the presentinvention.

FIG. 8A is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 8B is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 8C is a perspective view of an insert according to the presentinvention.

FIG. 8D is a perspective view of a channel apparatus according to thepresent invention.

FIG. 8E is a perspective view of an insert according to the presentinvention.

FIG. 9A is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 9B is a side cross-sectional view of the shale shaker of FIG. 9A.

FIG. 9C is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 9D is a side cross-sectional view of the shale shaker of FIG. 9C.

FIG. 9E is a perspective view of an insert according to the presentinvention.

FIG. 9F is a top view of the insert of FIG. 9E.

FIG. 9G is a is a perspective view of another insert according to thepresent invention.

FIG. 9H is a is a top view of the insert of FIG. 9G.

FIG. 10A is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 10B is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 10C is a perspective view of an insert according to the presentinvention.

FIG. 10D is a top view of the insert of FIG. 10C.

FIG. 10E is a perspective view of a channel apparatus according to thepresent invention.

FIG. 10F is a perspective view of an insert according to the presentinvention.

FIG. 10G is a perspective view of an insert according to the presentinvention.

FIG. 11A is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 11B is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 11C is a top view of an insert according to the present invention.

FIG. 11D is a top view of an insert according to the present invention.

FIG. 11E is a top view of an insert according to the present invention.

FIG. 12A is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 12B is a side cross-sectional view of the shale shaker of FIG. 12A.

FIG. 12C is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 12D is a side cross-sectional view of the shale shaker of FIG. 12C.

FIG. 12E is a perspective view of an insert according to the presentinvention.

FIG. 12F is a top view of the insert of FIG. 12E.

FIG. 12G is another perspective view of the insert of FIG. 12E whenviewed from an opposite side of the insert.

FIG. 13A is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 13B is a side cross-sectional view of the shale shaker of FIG. 13A.

FIG. 13C is a side cross-sectional view of a shale shaker according tothe present invention.

FIG. 13D is a side cross-sectional view of the shale shaker of FIG. 13C.

FIG. 13E is a perspective view of an insert according to the presentinvention.

Presently preferred embodiments of the invention are shown in theabove-identified figures and described in detail below. Various aspectsand features of embodiments of the invention are described below andsome are set out in the dependent claims. Any combination of aspectsand/or features described below or shown in the dependent claims can beused except where such aspects and/or features are mutually exclusive.It should be understood that the appended drawings and descriptionherein are of preferred embodiments and are not intended to limit theinvention or the appended claims. On the contrary, the intention is tocover all modifications, equivalents and alternatives falling within thespirit and scope of the invention as defined by the appended claims. Inshowing and describing the preferred embodiments, like or identicalreference numerals are used to identify common or similar elements. Thefigures are not necessarily to scale and certain features and certainviews of the figures may be shown exaggerated in scale or in schematicin the interest of clarity and conciseness.

As used herein and throughout all the various portions (and headings) ofthis patent, the terms “invention”, “present invention” and variationsthereof mean one or more embodiment, and are not intended to mean theclaimed invention of any particular appended claim(s) or all of theappended claims. Accordingly, the subject or topic of each suchreference is not automatically or necessarily part of, or required by,any particular claim(s) merely because of such reference. So long asthey are not mutually exclusive or contradictory any aspect or featureor combination of aspects or features of any embodiment disclosed hereinmay be used in any other embodiment disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a system S according to the present invention whichincludes a derrick 1 that extends vertically over a wellbore 2. Atubular work string 3 extends into the wellbore 2, and extends from theearth's surface to a desired depth within the wellbore. A flow line 4 ais connected to the tubular work string 3. A flow line 4 b is connectedto annular space 5 formed between the outer surface of tubular workstring 3 and the inner surface of wellbore 2.

Drilling fluid (or “mud”) for the system in a mud pit 6 is circulatedthrough the overall mud system via a mud pump 7. During typical drillingoperations, fluid is pumped into the tubular work string 3 by the mudpump 7 through the flow line 4 a, circulated out a bottom end 3 a of thetubular work string 3 (e.g., but not limited to, out from a drill bit9), up an annulus 5 of the wellbore 2, and out of the annulus 5 via theflow line 4 b.

Spent (or used) fluid mud exiting the wellbore annulus 5 through theflow line 4 b includes drilling fluid, drill cuttings, lost circulationmaterial (and/or material of similar size), and other debris encounteredin the wellbore 2. Accordingly, the spent drill cuttings mixture leavingthe well is directed to a separation device, such as one or more shaleshakers 8 according to the present invention. The combined mixture ofdrilling fluid, added material (e.g. solids and/or lost circulationmaterial, etc.), debris, and drilled cuttings are directed to the shaleshakers 8. Liquid drilling fluid passes through screens at the same orat different levels of the shaker, e.g. screens 8 a, 8 b, 8 c, 8 d whichare at four different levels of the shale shakers 8 and is directed intothe mud pit 6 (or the two lowermost screens are at the same level eachreceiving a portion of flow from the screen 8 b). Drill cuttings andother solids pass over the screens 8 a-8 d of the shale shakers 8 andare discharged (arrows 8 e, 8 f, 8 g, 8 h). With the proper selection ofscreen mesh for the screen 8 b, lost circulation material (with somematerial of similar size, if present) is separated by and dischargedfrom the top of the screen 8 b (see arrow 8 f). The recovered lostcirculation material (and/or material of similar size) flows and/or ispumped to a mud pit, a reservoir, or to a further processing apparatus 8k. Optionally, the shale shakers 8 are like any other shale shakerdisclosed herein according to the present invention. One, two, or morescreens in series may separate selected material (e.g., but not limitedto, lost circulation material) that flows and/or is pumped to areservoir or to the further processing apparatus 8 k.

Referring now to FIG. 1A, a shale shaker H according to the presentinvention has screens A1, A2, A3, A4, each of which is, according to thepresent invention, at one of four different levels (with screen orscreening cloth or mesh as desired). The screens are mounted onvibratable screen mounting apparatus or “basket” B. The screens A1, A2,A3, A4, according to the present invention, may be any suitable knownscreen or screens, with the screen A2 (or the screens A2 and A3) used toseparate lost circulation material (and/or material of similar size).The basket B is mounted on springs C (only two shown; two as shown areon the opposite side) which are supported from a frame D. The basket Bis vibrated by a motor and interconnected vibrating apparatus E which ismounted on the basket B for vibrating the basket and the screens.Elevator apparatus F provides for raising and lowering of the basketend. Fluid passing through the screens A1, A2, A3, and A4 flows into areceptacle R beneath the bottom screen A4. In certain aspects screen A1has the coarsest mesh of all the screens and acts as a scalping screenand the screens A3 and A4 provide fine screening. The exit feeds fromthe top sides of the screens A1, A3, A4 may go to disposal or may bedirected as described below for any embodiment of the present invention.The lost circulation material recovered from the top of the screen A2(or, optionally, from the tops of the screens A2 and A3) may be flowed,processed and treated as described for any embodiment of the presentinvention. As shown, the screens A3, A4 operate in series, i.e., theunderflow from the screen A3 flows down to the screen A4. Optionally,the screens A3, A4 may be operated in parallel with each receiving aportion of screen A2's underflow.

FIGS. 2A and 2B show a system 10 according to the present inventionwhich includes a shale shaker 12 with a base 14 and a screen-supportingbasket 16. A vibrator apparatus 18 vibrates the basket 16 and screensmounted in it.

Four spaced-apart screens 21-24 are mounted in the basket 16 atdifferent levels (e.g. spaced-apart six to eight inches) or put anotherway, at four different heights in the basket. In one particularembodiment the screen 21 is a scalping screen which, in one particularaspect removes relatively large pieces of material, e.g. with mesh sizedso that pieces ⅛″ and 1/64″ are used. In one aspect, the screen 21 has amesh size such that pieces greater than 1/16″ are removed (and piecesof, among other things, solids and/or lost circulation material that are1/16″ or smaller in largest dimension pass through the screen 21 (e.g.,but not limited to graphite ball lost circulation material that are1/16″ in largest dimension or slightly smaller).

The screen 22 has a mesh size as chosen for removing material of acertain largest dimension or larger, including, but not limited tosolids, debris, drilled cuttings, desirable additives, and/or lostcirculation material. In one aspect the mesh size is chosen incooperation with the mesh size of the screen 21 so that the screen 22removes lost circulation material (and solids or pieces of similar size)and, in one particular aspect the mesh size is chosen so that lostcirculation material of a largest dimension of 1/16″ or greater does notpass through the screen 22 and flows from the top thereof. In one aspectsuch lost circulation material is graphite balls.

The screens 23 and 24 further filter out solids from the flow throughthe screen 22 and, in certain aspects, the screens 23 and 24 act astypical standard fine screening screens used to process a mixture ofdrilling fluid and solids.

The exit streams from screens 21, 23, and 24 exit from the tops of theirrespective screens and flow down to a container, system or apparatus 20for storage and/or further processing. Drilling fluid flowing throughthe screens flows down to a sump or container 26 and from there to areservoir or, in one aspect, back to an active rig mud system. The exitstream from the screen 22, in particular aspects, has wet lostcirculation material (or wet lost circulation material along with solidsof similar size) of at least 50% by volume; and in one particular aspectat least 75% lost circulation material by volume (in one example, theoutput is 50% lost circulation material and 50% solids of similar size).In certain aspects, screen mesh size is chosen so that a relativelylarge percentage of the flow off the top of the screen is lostcirculation material, e.g. by volume, up to 50%, 75%, or up to 90%.

Fluid with some solids therein (including the lost circulation materialof a certain size, if present) that flows through the screen 21 isdirected to the screen 22 by a flowback barrier (or plate) 31.Optionally, the flowback barrier 31 is eliminated. The material(including lost circulation material of a certain size, if present) thatexits from the top of the screen 22 is transferred to a reclamationsystem 40 (which, in one aspect, is, has or includes an auger apparatus42 for moving solids to and/or from the reclamation apparatus) orflushed to a mud pit.

Fluid with solids that flows through the screen 22 is directed to thescreens 23 and 24 by a flowback barrier or plate 32, a flow channel 32a, and a weir 32 b. Fluid with solids that flows through the screen 23is directed to the sump 26 through a channel 51 by a flowback barrier 33and a channel 33 a. When the level of fluid (with material therein)exceeds the height of the weir 32 b, part of the flow from the screen 22flows into the flow channel 50 bypassing the screen 23 and flowing tothe screen 24 (thus, the screens 23, 24 in this manner operate inparallel). Fluid flowing through the screen 24 flows into the sump 26.Optionally, the screen 21 includes an end weir 21 w and fluid andmaterial on top of the screen 21 in a pool 21 p that exceeds the heightof the weir 21 w bypasses the screen 21 and flows to the screen 22 via achannel 17. The flowback barriers extend under substantially all of thesurface of the particular screens under which they are located. Any one,two, or three of the flowback barriers can, optionally, be eliminated.

The screens 21-24 are at typical screen tilt angles, e.g. between 6degrees to 12 degrees from the horizontal and in certain aspects, atabout 7 degrees or about 8 degrees.

A shale shaker 10 a shown in FIG. 2C is like the system 10, FIG. 2A (andlike numerals indicate like parts). Two screens, the screens 22 and 23,are used in the shale shaker 10 a to remove LCM material (and/ormaterial of similar size). The two screens 22, 23 act in parallel withflow from the upper screen 21 flowing both to the screen 22 and, over aweir 22 w, to the screen 23. Fluid flowing through the screen 22 flowsto a channel 50 a and then down to the screen 24 as does fluid flowingthrough the screen 23.

FIGS. 3A and 3B show a shaker system 10 b like the system 10, FIG. 2A(like numerals indicate like parts). The shaker 10 b has a collectionchute 60 which receives material from top of a screen 21 a (like thescreen 21, FIG. 2A) and from which the material flows down to a cuttingsditch, pit, or collector 19. An auger system 70 receives material fromthe top of a screen 22 a (like the screen 22) and augers the materialinto a conduit 70 a from which it flows to storage or further processingapparatus 70 b or is flushed to a mud pit. The flows from the tops ofscreens 23 a (like screen 23) and 24 a (like screen 24) flow to thecuttings ditch (etc.) 19. Fluid flowing through the screens flows to asump 26 a (like the sump 26). In one aspect, the screen 22 a is used torecover LCM (and/or material of similar size). Optionally, as in FIG.2C, both screens 22 a and 23 a are used to recover LCM (and/or materialof similar size).

Material recovered from the top of a second screen in systems accordingto the present invention (e.g. from the top of the screen 8 b, 21 or 21a) can, according to the present invention, be sent to additionaltreatment apparatus for further processing; including, but not limitedto, a sprinkle-wash system for solids recovery, centrifuge(s),hydrocyclone(s), and/or magnetic separation apparatus. This materialfrom the tops of these screens is, in one aspect, lost circulationmaterial. In one aspect, considering the totality (100%) of the lostcirculation material in a drilling fluid mixture fed to a top scalpingscreen of a system according to the present invention, about 97% of thislost circulation material flows to the second screen and about 95% (95%of the original totality of the material) is recovered from the top ofthe second screen; or optionally, a combination of similar sizedmaterial, including both LCM and other material is recovered.

FIGS. 4A and 4B illustrate a quad-tier system 100 according to thepresent invention which has screen decks 101, 102, 103, and 104. A feed105 of a drilling fluid mixture is fed onto a first deck 101 with aplurality of screens 101 a, 101 b, 101 c (may be any suitable number ofscreens). Drilling fluid (with some solids) flowing through the screens101 a-101 c flows to a chute 106 and from there down to the deck 102.Overflow 107 from the deck 101 flows over a weir 108 (of apre-determined height) down to the deck 102. Oversized material 109flows off the top of the screen 101 c.

Drilling fluid with some solids flowing through screens 102 a (fourshown; may be any suitable number of screens) flows to chutes 116 andfrom there to the deck 103. Oversize material 119 flows off the tops ofscreens 102 a. A weir 118 prevents any overflow from the top of thescreens 102 a from flowing down to the deck 103.

Drilling fluid with some solids flowing through screens 103 a (sizeshown; may be any number) of the deck 103 flows to a diverter 126 andfrom there to a collection structure, e.g. a tank, sump or receptacle.Overflow from the top of the screens 103 a flows to a channel apparatus128 and from there to a channel apparatus 138 which directs this flow tothe top of the deck 104. Oversized material 129 flows off the tops ofend screens 103 a.

Drilling fluid flowing through screens 104 a (four shown; any number maybe used) flows down to chutes 136 and then to the tank, sump, orreceptacle. Oversized material 139 flows off tops of end screens 104 a.

The oversized material flows, 109, 119, 129 and 139 flow to typicalcollection sump, pit tank, or receptacle or storage apparatus and/or tosubsequent processing apparatus.

In one particular aspect of the system 100, the deck 101 is a coarsescreening deck (e.g. but not limited to the screen 8 a, screen A1,screen 21 or screen 21 a); the deck 102 is a medium mesh screening deck(e.g. but not limited to, like the screen 8 b, screen A2, screen 22, orscreen 22 a); the deck 103 is a medium or fine screening deck (e.g., butnot limited to, like the screen 8 c, screen A3, screen 23 or screen 23a); and the deck 104 is a fine screening deck (e.g., but not limited to,like the screen 8 d, screen A4, screen 24 or screen 24 a).

FIGS. 5A′, 5A″, and 5B illustrate a system 200 according to the presentinvention which is, in some ways, like the system 100, FIG. 4A. In thesystem of FIG. 4A underflow from the deck 102 flows to both the deck 103and the deck 104. In the system 200 flow from the deck 101 flows to boththe deck 102 and the deck 103, with underflow from both of these decksflowing to the deck 104.

Drilling fluid with some solids (underflow from the deck 101) flows fromthe deck 101 down to the deck 102. Overflow from the deck 102 flows viathe channel apparatus 128 a and channel apparatus 204 to the deck 103.Underflow from the deck 102 flows to the chutes 116 and is diverted tothe deck 104 by a diverter 202 (with handles 203) and via a channelapparatus 206 and a channel apparatus 208 to the deck 104. In one aspectthe diverter 202 is connected to the channel apparatus 204 (indicated bythe wavy lines on both).

Underflow having passed through the deck 103 and chutes 116 a (like thechutes 116) is diverted by a diverter 202 a (like the diverter 202) tothe deck 104. Underflow having passed through the deck 104 flows to thechutes 136 and then to collection, storage, tank, or receptacle.

The various chutes, diverters, and channel apparatuses in the systems100 and 200 are interchangeable, in one aspect, so that series orparallel flow to and from one or more selected decks is facilitated. Incertain aspects, the chutes, diverters and channel apparatuses are madeof metal, plastic, or composite material.

In the system 100, FIG. 4A, the channel apparatus 128 has three flowpassages 128 a, 128 b, 128 c. The diverter 126 has two flow passages 126a, 126 b. The channel apparatus 138 has flow passages 138 a, 138 b, 138c. In the system 200, FIG. 5A, the channel apparatus 128 a has flowchannels 128 c, 128 d. The channel apparatus 204 has flow passage 204 a,204 b. The channel apparatus 206 has flow passages 206 a, 206 b. Thechannel apparatus 208 has flow passages 208 a, 208 b.

The present invention, therefore, provides in at least certainembodiments, a system for processing a mixture of drilling fluid andsolid material to separate at least one component of the mixture by sizefrom the mixture, the system including a vibratable basket; a sump at abottom of the basket; a plurality of spaced-apart screens including afirst screen deck, a second screen deck positioned below the firstscreen, a third screen deck positioned below the second screen deck, anda fourth screen deck positioned below the third screen; the screensmounted in the vibratable basket and vibratable therewith; the firstscreen deck having screen mesh of a first size to remove from a top ofthe first screen deck solids from the mixture with a largest dimensionequal to and larger than a first dimension so that material with alargest dimension smaller than the first dimension is passable downthrough the first screen deck; the second screen deck having screen meshof a second size to remove from a top of the second screen solids fromthe mixture passing to the second screen deck from the first screen deckwhich have a largest dimension equal to or larger than the second sizeso that material with a largest dimension smaller than the second sizeis passable down through the second screen deck, material and fluidpassing through the second screen deck comprising a secondary flow;diversion apparatus connected to the basket positioned for providing atleast a portion of the secondary flow to the third screen deck and,selectively, a portion of the secondary flow to the fourth screen deck;the third screen deck having screen mesh of a third size, and the fourthscreen deck having screen mesh of a fourth size for removing solids fromthe secondary flow on the top of the third screen deck and from the topof the fourth screen deck; and drilling fluid flowing through the firstscreen deck, the second screen deck and one of the third screen deck andfourth screen deck flowing down into the sump. Such a system may haveone or some, in any possible combination, of the features and aspectsdescribed above for any system according to the present invention.

The present invention, therefore, provides in at least certainembodiments, a system for processing a mixture of drilling fluid andsolid material to separate at least one component of the mixture by sizefrom the mixture, the system including: a vibratable basket; a sump at abottom of the basket; a plurality of spaced-apart screens including afirst screen deck, a second screen deck positioned below the firstscreen, a third screen deck positioned below the second screen deck, anda fourth screen deck positioned below the third screen; the screensmounted in the vibratable basket and vibratable therewith; the firstscreen deck having screen mesh of a first size to remove from a top ofthe first screen solids from the mixture with a largest dimension equalto and larger than a first dimension so that material with a largestdimension smaller than the first dimension is passable down through thefirst screen deck; the second screen deck having screen mesh of a secondsize to remove from a top of the second screen solids from the mixturepassing to the second screen deck from the first screen deck which havea largest dimension equal to or larger than the second size so thatmaterial with a largest dimension smaller than the second size ispassable down through the second screen deck, material and fluid passingthrough the second screen deck comprising a secondary flow; diversionapparatus connected to the basket positioned for providing at least aportion of the secondary flow to the third screen deck and, selectively,a portion of the secondary flow to the fourth screen deck; the thirdscreen deck having screen mesh of a third size, and the fourth screendeck having screen mesh of a fourth size for removing solids from thesecondary flow on the top of the third screen deck and from the top ofthe fourth screen deck; drilling fluid flowing through the first screendeck, the second screen deck and one of the third screen deck and fourthscreen deck flowing down into the sump; wherein the first screen deck isa scalping deck; wherein the screen mesh of a second size is suitablefor removing solids the size of lost circulation material, said solidsincluding pieces of lost circulation material and pieces of materialother than lost circulation material; the drilling fluid mixtureintroduced to the system to be treated by the system includes a firstamount of lost circulation material; the second deck is able to remove asecond amount of lost circulation material; the second amount at least75% of the first amount; and reclamation apparatus for receiving thelost circulation material.

The present invention, therefore, provides in at least certainembodiments, a method for treating a mixture of drilling fluid and solidmaterial to separate at least one component of the mixture by size fromthe mixture, the method including: feeding the mixture to a vibratablebasket of a system, the system as any described herein according to thepresent invention, and the method further including flowing drillingfluid through a first screen deck, a second screen deck and one of athird screen deck and a fourth screen deck of the system down into asump; or flowing drilling fluid through a first screen deck, and one ofa second screen deck and a third screen deck flowing down into a sump.

FIGS. 6A-6D show a shale shaker 310 according to the present inventionwhich has a basket 312 vibrated by vibratory apparatus 314 and a lowersump 316 which receives fluid (or fluid and some solids) that passesthrough three screens 318 a, 318 b, 318 c which are mounted to thebasket 312 at different levels.

Fluid from the screen 318 a flows down to a flowback barrier 317 a,through an opening 328, and then onto the screen 318 b. As this fluidbuilds up into a pool 315 a on the screen 318 b, it rises to a levelequal to and then greater than a top 313 a of a weir 313. Fluid thenflows over the top 313 a of the weir 313 through a channel 311 to thelower screen 318 c. The opening 328 is defined by the weir 313 and anend of the flowback barrier 317 a.

Fluid that flows through the screen 318 b flows down a flowback barrier317 b, over an end of a diverter 320, and down to the sump 316 via achannel 316 a.

The diverter 320 is selectively movable in holding structure 320 a and,as in FIG. 6A, blocks an opening 322 of a channel 324 formed byspaced-apart members 325, 326. As shown in FIG. 6B, the diverter 320prevents fluid that has exited from the bottom of the screen 318 b fromflowing onto the screen 318 c. This fluid flows past the opening 322into the channel 316 a. FIGS. 6A and 6B illustrate a parallel fluid flowpath.

As shown in FIGS. 6C and 6D, the diverter 320 has been moved so thatfluid is flowable down onto the screen 318 c which has exited throughthe bottom of the screen 318 b. This is an “in series” flow path—fromthe screen 318 a to the screen 318 b to the screen 318 c—for fluid downto the sump 316.

The diverter 320 can be manipulated and moved through an open end accessarea 329 (FIG. 6F) of the basket 312. As shown in FIG. 6E, the diverter320 has a solid chute portion 320 a for facilitating fluid flow and twohandles 320 b projecting from the chute portion 320 a.

The angle from the horizontal of the screen 318 b coupled with theheight of the weir 313 determines the depth of the pool 315 a and of alower edge 318 e of a beach area 318 f on the screen 318 b (e.g., seeFIG. 6C).

Fluid flowing through the screen 318 c flows down a flowback barrier 317c into the sump 316. Solids (wet to some degree) flow off the ends ofthe screens as indicated by the arrows W.

The diverter 320 is mounted between rails 321 of the holding structure320 a (see, e.g., FIG. 6G) and clamping apparatuses 320 p, 320 s areused to hold the diverter 320 in place. Any suitable clamping apparatusmay be used including, without limitation, pneumoseal apparatuses.Clamping apparatuses 310 p hold the screens in place.

FIGS. 7A and 7B show a shale shaker 340 according to the presentinvention with a basket 342 vibrated by vibratory apparatus 344. Screens346, 347, 348 are mounted in the basket with a flowback barrier 345beneath the screen 346 and flowback barrier 343 beneath the screen 347.

A weir 341 with a top end 341 a defines (with an end 342 a of the basket342) a flow channel 349 for fluid flowing over the top 341 a of the weir341 from a pool 351 of fluid on the screen 347. Fluid flowing down inthe channel 349 flows to the lowermost screen 348. Fluid flowing throughthe screen 348 flows into a sump 356.

The screen 347 has flow barrier 352 (see FIG. 7C) connected therebelowwith an end 353 which, in the position shown in FIG. 7A, blocks anopening 354 (see, FIG. 7B) so that fluid flowing in the channel 349cannot flow into a channel 359. Also, with the opening 354 blocked,fluid flowing down through the screen 347 flows along the flowbackbarrier 343 to the opening 354, into the channel 359, and then into thesump 356. Thus the flow mode for the screens 347 and 348 as shown inFIG. 7A is parallel-fluid flowing through the screen 347 does not flowto the screen 348.

As shown in FIG. 7B, the screen 347 does not have the flow barrier 352below it and the channel 359 is closed to fluid flow by a flow barrier362. With the channel 359 closed by the flow barrier 362 and with theend 353 removed from the opening 354, fluid flowing through the screen347 flows onto the screen 348 and thus the flow mode, as shown in FIG.7B, is in series for the screens 347, 348.

As shown in FIG. 7C, for parallel flow, the flow barrier 352 has a body363 with a flow channel 355 therethrough; a solid portion 350; and anend connection 357 for connection to the screen 347. As shown in FIG. 7Dthe flow barrier 362 has a body 358 with a flow channel 360 therethroughand a connection 361 for connection to the screen 347. FIG. 7Dillustrates the flow path for series flow.

FIGS. 8A and 8B show a shale shaker 370 according to the presentinvention with a basket 372 vibrated by vibratory apparatus 374. Screens376, 377, 378 are mounted in the basket with a flowback barrier 375beneath the screen 376 and flowback barrier 373 beneath the screen 377.

A weir 371 with a top end 371 a defines (with an end 372 a of the basket372) a flow channel 379 for fluid flowing over the top 371 a of the weir371 from a pool 381 of fluid on the screen 377. Fluid flowing down (FIG.8A) in the channel 379 flows to the lowermost screen 378. Fluid flowingthrough the screen 378 flows along a flowback barrier 394 into a sump386.

The screen 377 has an insert 390 at an end 377 a which is in theposition shown in FIG. 8A. Fluid flowing through the screen 377 flowsinto a flow channel 393 of a channel apparatus 391 (see FIG. 8D)positioned in an opening 397 at an end 378 a of the screen 378_and theninto the sump 386. Pneumoseal apparatus 389 p, 389 s facilitates theclamping in place of the screens and inserts, and the maintenance of thescreens and inserts in a desired position.

Fluid from the pool 381 flowing over the top 371 a of the weir 371 flowsin the channel 379 down to the screen 378. Fluid flowing through thescreen 378 flows into the sump 386. Thus the flow from the screen 376 toand through the screens 377, 378 is in a parallel flow mode.

As shown in FIG. 8B, the insert 390 and the channel apparatus 391 havebeen removed, and the screen 377 has been moved down so that the end 377a now occupies the position of the insert 390. Fluid flowing through thescreen 376 flows down to the screen 377. Then fluid flowing through thescreen 377 flows down to the screen 378 through an opening 374. Aninsert 392, FIG. 8E, replaces the channel apparatus 391 at the lower end378 a of the screen 378 and blocks flow through the opening 397 (seeFIG. 8 a).

FIGS. 9A-9D show a shaker 400 with a sump 416 and basket 402 vibrated byvibratory apparatus 404. Screens 411, 412, and 413 are mounted in thebasket 402. A flowback barrier 401 is below the screen 411, a flowbackbarrier 414 is below the screen 412, and a flowback barrier 415 is belowthe screen 413.

A weir 405 having a top end 405 a with an end portion 402 a of thebasket 402 defines a channel 409 through which flows fluid coming overthe top end 405 a of the weir 405 from a pool 406 of fluid on the screen412. Fluid flows down and out of the channel 409 to contact and flowthrough an insert 417 positioned at an end 412 a of the screen 412.Fluid flows through a passageway 418 in the insert 417 (see FIGS. 9E-9F)to a channel 419 and down to the screen 413. Thus fluid flows from thescreen 411 to both the screens 412 and 413 in a parallel flow mode.

Fluid flowing through the screen 412 flows to and through channels 417a, 417 b in the insert 417, from there into a channel 410, and down tothe sump 416.

FIGS. 9C and 9D show the shaker 400 in a series flow mode. As shown inFIGS. 9C and 9D, an insert 424 (see FIGS. 9G and 9H) is positioned atthe end 412 a of the screen 412, replacing the insert 417. Insert 424blocks the flow of any fluid that may overflow the top end 405 a of theweir 405 and enter the channel 409. Fluid flowing from the screen 412flows down the flowback barrier 414 therebelow, passes through a channel425 in the insert 424 and then down, via the channel 419 onto the screen413. As in FIGS. 9A and 9B, pneumoseal apparatuses 400 p, 400 s holdscreens and inserts in place.

FIGS. 10A and 10B show a shale shaker 430, in parallel flow mode in FIG.10A and in series flow mode in FIG. 10B. The shale shaker 430 has abasket 438 vibrated by a vibratory apparatus 434. A flowback barrier 437is below a screen 431; a flowback barrier 435 is below a screen 432; anda flowback barrier 436 is below a screen 433. The flowback barrier 435has a channel 435 a in an end 435 b. Pneumoseal apparatuses 430 p, 430 shold screens and inserts in place.

Fluid flowing through the screen 431 flows to both the screen 432 and tothe screen 433 from a pool 429 on the screen 432, over a weir 444,through a channel 427, and through an opening 439 a in an insert 439(see FIGS. 10C, 10D)_positioned at an end 432 a of the screen 432. Fluidflowing through the screen 432 flows to a channel 441 of a channelapparatus 442 (see FIG. 10E) positioned at an end 433 a of the screen433 and then to a sump 446. Fluid flowing through the screen 433 flowsdown to the sump 446.

As shown in FIG. 10B, an insert 448 (see FIG. 10F) is positioned at theend 432 a of the screen 432, replacing the insert 439, and blocks flowthrough the channel 427. Additionally, an insert 449 (see FIG. 10G) ispositioned at the end 433 a of the screen 433, replacing the channelapparatus 442, and blocks flow through an opening 449 a (see FIG. 10A)so that all fluid flowing from the screen 431 flows to the screen 432.Via the opening 435 a, all fluid flowing from the screen 432 flows tothe screen 433.

FIGS. 11A and 11B show a shale shaker 450 with a basket 452 vibrated bya vibratory apparatus 454. A flowback barrier 457 is beneath a screen461 and a flowback barrier 458 is beneath a screen 462. Fluid flowingthrough a screen 463 flows into a sump 456. Pneumoseal apparatuses 450p, 450 s hold screens and inserts in place.

Fluid from a pool 459 on the screen 462 overflows a top end 464 a of aweir 464, through a channel 465, onto the screen 463 (as shown in FIG.11A). Fluid flowing through the screen 462 flows through a channel 453in an insert 451 (see FIG. 11D) and then into the sump 456 (not onto thescreen 463). The insert 451 is mounted in a mount 467 and the channel453 is in fluid communication with a flow channel 471, permitting thefluid flowing through the screen 462 to flow into the channel 471. Thus,the fluid flowing through and then down from the screen 461 flows bothto the screen 462 and (over the weir 464) to the screen 463, i.e. in aparallel flow mode. An insert 474 (see FIG. 11C) at the end 462 a of thescreen 462 holds the screen 462 in such a position that height of thepool 459 makes possible the flow of fluid over the weir 464, so thatseries or parallel flow can be achieved.

FIG. 11B illustrates a series flow mode for the shaker 450. An insert472 now replaces the insert 451 in the mount 467, and blocks the openingto the channel 471 so that fluid flowing through the screen 462 flowsdown onto the screen 463 (not directly into the sump 456 through thechannel 471). Additionally, the insert 474 has been removed and thescreen 462 has been moved down so that the end 462 a now occupies theposition of the insert 474. Some overflow, if any, from the pond on thescreen 462 could flow over the weir 464 down to the screen 463.Optionally a cut-out portion 479 of the insert 472 provides a handle(see FIG. 11E). Furthermore, in other embodiments, the insert 451 may bedesigned so that when changing the shaker 450 from a parallel flow modeto a series flow mode, the insert 451 may be removed, reversed, andreinstalled so that the channel 453 is no longer positioned above theflow channel 471, and therefore no longer provides fluid communicationthereto. Instead, the insert 451 may be designed so as to block theopening to the channel 471, thereby facilitating series flow from thescreen 462 to the screen 463, as described above.

FIGS. 12A and 12B show the shale shaker 480 with a basket 482 vibratedby vibratory apparatus 484. Fluid flowing through a lowermost screen 493flows into a sump 496. A flowback barrier 481 is beneath a top screen491 and a flowback barrier 483 is beneath a middle screen 492. Aflowback barrier 486 is beneath the screen 493. Pneumoseal apparatuses480 p, 480 s hold screens and inserts in place.

In a parallel flow mode as illustrated in FIGS. 12A, 12B, fluid flowingthrough the screen 491 flows to both the screen 492 and from a pool 489on the screen 492 over a top end 487 a of a weir 487 via a flow channel488 down to the screen 493. An insert 498 (see FIGS. 12E, 12F) in amount 497 has an opening 498 a through which fluid from the channel 488flows to the screen 493. At the same time, fluid from the screen 492 isdeflected by a plate portion 498 d of the insert 498 and flows throughopenings 498 b to a channel 485 and to the sump 496.

FIGS. 12C and 12D show the shale shaker 480 in series flow mode. Asshown in FIG. 12C, fluid has flowed through the screen 491 down to thescreen 492, and the insert 498 has been flipped and rotated in the mount497 (as shown in FIG. 12G) so that the positions of the openings 498 aand 498 b relative to the flow channels 488 and 485, respectively, havebeen reversed. Fluid flowing through the screen 492 flows to the opening498 a in the insert 498 and then down to the screen 493. In the reversedinstallation of the insert 498 shown in FIG. 12C, plate portions 498 con either side of the opening 498 a in the insert 498 (see FIG. 12G) canblock fluid flow through the channel 485. Similarly, as shown in FIG.12D, the plate portion 498 d between the two openings 498 b in theinsert 498 can also block fluid flow from the channel 488.

FIGS. 13A and 13B show a shale shaker 500 in a parallel flow mode. Theshaker 500 has a basket 507 and screens 501-503 vibrated by a vibratoryapparatus 504. Flowback barriers 511-513 are, respectively, locatedunder the screens 501-503. An insert 530 in a mount 540 is used tochange operational mode from series to parallel and vice-versa.Pneumoseal apparatuses 500 p, 500 s hold screens in place.

As shown in FIG. 13A fluid from the screen 501 flows both to the screen502 and to the screen 503 (from a pool 509 on the screen 502, over aweir 534, through a channel 505, and through an opening 530 b in theinsert 530). As shown in FIG. 13B fluid from the screen 502 flows to thesump 506 (down the flowback barrier 512, through openings 530 a in theinsert 530, to a channel 551 of a channel apparatus 550, and to the sump506). Fluid from the screen 503 flows down the flowback barrier 513 tothe sump 506.

FIGS. 13C and 13D illustrate the shaker 500 in a series flow mode. Asshown in FIG. 13C, the insert 530 (turned around) has been moved forwardin the mount 540 so that the opening 530 b is no longer aligned with thechannel 505, and the openings 530 a are no longer aligned with thechannel 551. In this position, the insert 530 blocks fluid flow from thechannel 505 so that only the screen 502 receives the fluid flowing fromthe screen 501. The insert 530 also blocks fluid flow through thechannel 551 so that all the fluid flowing from the screen 502 flows tothe screen 503.

As shown in FIG. 13E, the insert 530 hasopenings 530 a (for flow fromscreen 502 to the channel 551) and an opening 530 b (for flow from thepool 509 through the channel 505) to facilitate operation of the shaleshaker 500 in a parallel flow mode.

Any screen assembly, any diverter, any pair of screen assemblies, and/orany insert according to the present invention (including, withoutlimitation those of FIGS. 6A-13E) may be used with any shaker or systemaccording to the present invention disclosed herein.

The present invention, therefore, provides in at least certainembodiments, a system for processing a mixture of drilling fluid andsolid material to separate at least one component of the mixture by sizefrom the mixture, the system including: a vibratable basket forreceiving an input flow of drilling fluid with solids therein; aplurality of spaced-apart screen assemblies including a first screenassembly and a second screen assembly positioned below the first screenassembly; the screen assemblies mounted in the vibratable basket andvibratable therewith; conversion apparatus associated with the screenassemblies for selectively controlling the input flow to select one ofseries flow and parallel flow to the screen assemblies; drilling fluidflowable through the first screen assembly; and drilling fluid flowablethrough the second screen assembly and flowable down therefrom. Such asystem may one or some, in any possible combination, of the following: asystem flow channel between the first screen assembly and the secondscreen assembly, the conversion apparatus including holding structureabove the second screen assembly, a diverter held by the holdingstructure, the diverter having a diverter channel therethrough throughwhich fluid is flowable from the first screen assembly through thesystem flow channel down to the second screen assembly for series flowof the input flow from the first screen assembly to the second screenassembly, a weir adjacent the first screen assembly forming a barrier tofacilitate maintenance of a pool of drilling fluid and solids on thefirst screen assembly, and the diverter having a blocking portion, thediverter movable to block flow through the system channel so that thepool rises and drilling fluid with solids bypasses the first screenassembly and flows to the second screen assembly for parallel flow ofthe input flow to both screen assemblies; the holding structure havingspaced-apart rails and having an end opening, and the diverter locatedbetween the rails and having handle apparatus at the end opening, thehandle apparatus accessible for moving the diverter with respect to thesystem flow channel; flowback apparatus beneath the first screenassembly for directing flow passing through the first screen assembly tothe system flow channel; a sump beneath the second screen assembly forreceiving flow passing through the screen assemblies; a parallel flowchannel adjacent the screen assemblies for directing flow from the poolto the second screen assembly bypassing the first screen assembly duringparallel flow of the system; holding structure above the second screenassembly, and clamping apparatus for holding the diverter in the holdingstructure; wherein the first screen assembly includes a scalping screen;wherein the second screen assembly includes a screen with second screenmesh of a size suitable for removing solids the size of lost circulationmaterial; a system flow channel between the first screen assembly andthe second screen assembly through which fluid is flowable from thefirst screen assembly to the second screen assembly, the conversionapparatus having a body, the body having a blocking portion for blockingflow to the system flow channel to effect system parallel flow of theinput flow to both screen assemblies, and the body having a flow ductfor receiving flow from the first screen assembly which is flowablethrough the duct to the second screen assembly for system series flow tothe screen assemblies; a duct blocker for blocking flow through theduct; and/or the conversion apparatus having a body, a first flowchannel through the body for effecting system parallel flow to thescreen assemblies, and a second flow channel through the body foreffecting system series flow to the screen assemblies.

The present invention, therefore, provides in at least certainembodiments, a system for processing a mixture of drilling fluid andsolid material to separate at least one component of the mixture by sizefrom the mixture, the system including: a vibratable basket forreceiving an input flow of drilling fluid with solids therein; aplurality of spaced-apart screen assemblies including a first screenassembly and a second screen assembly positioned below the first screenassembly; the screen assemblies mounted in the vibratable basket andvibratable therewith; conversion apparatus associated with the screenassemblies for selectively controlling the input flow to select one ofseries flow and parallel flow to the screen assemblies; drilling fluidflowable through the first screen assembly and drilling fluid flowablethrough the second screen assembly and down therefrom; a system flowchannel between the first screen assembly and the second screenassembly; the conversion apparatus having a body, a first flow channelthrough the body for effecting system parallel flow to the screenassemblies, a second flow channel through the body for effecting systemseries flow to the screen assemblies; flowback apparatus beneath thefirst screen assembly for directing flow passing through the firstscreen assembly to the system flow channel; a sump beneath the secondscreen assembly for receiving flow passing through the screenassemblies; and a parallel flow channel adjacent the screen assembliesfor directing flow from the pool to the second screen assembly bypassingthe first screen assembly during parallel flow to the screen assemblies

The present invention, therefore, provides in at least certainembodiments, a conversion apparatus for a system for processing amixture of drilling fluid and solid material to separate at least onecomponent of the mixture from the mixture, the system including avibratable basket for receiving an input flow of drilling fluid withsolids therein, a plurality of spaced-apart screen assemblies includinga first screen assembly and a second screen assembly positioned belowthe first screen assembly, the screen assemblies mounted in thevibratable basket and vibratable therewith, drilling fluid flowablethrough the first screen assembly and the second screen assembly downtherefrom, the conversion apparatus associated with the screenassemblies for selectively controlling the input flow to select one ofseries flow and parallel flow, the conversion apparatus including: abody, a first flow channel through the body for effecting systemparallel flow to the screen assemblies, and a second flow channelthrough the body for effecting system series flow to the screenassemblies.

The present invention, therefore, provides in at least certainembodiments, a method for treating a flow of drilling fluid with solids,the method including: introducing the flow of drilling fluid with solidsto a system for separating at least one component from the flow, thesystem as any disclosed herein according to the present invention; themethod further including: selecting one of a system series flow toscreen assemblies of the system or a system parallel flow to the screenassemblies using a conversion apparatus; flowing drilling fluid withsolids to the screen assemblies; and screening the flow to eachscreening assembly. Such a method may one or some, in any possiblecombination, of the following: wherein the conversion apparatus has abody, a first flow channel through the body for effecting systemparallel flow to the screen assemblies, and a second flow channelthrough the body for effecting system series flow to the screenassemblies, the method further including selecting the first flowchannel for system parallel flow or selecting the second flow channelfor system series flow; wherein the system further has flowbackapparatus beneath the first screen assembly for directing flow passingthrough the first screen assembly to the system flow channel, the methodfurther including directing flow from the first screen assembly to thesystem flow channel; wherein the system further has a sump beneath thesecond screen assembly, the sump receiving flow passing through thescreen assemblies; wherein the system further has holding structureabove the second screen assembly, and clamping apparatus for holding thediverter in the holding structure, the method further including clampingthe diverter with the clamping apparatus; and/or wherein the firstscreen assembly includes a scalping screen, and wherein the secondscreen assembly includes a screen with second screen mesh of a secondsize suitable for removing solids the size of lost circulation material.

In conclusion, therefore, it is seen that the present invention and theembodiments disclosed herein and those covered by the appended claimsare well adapted to carry out the objectives and obtain the ends setforth. Certain changes can be made in the subject matter withoutdeparting from the spirit and the scope of this invention. It isrealized that changes are possible within the scope of this inventionand it is further intended that each element or step recited in any ofthe following claims is to be understood as referring to the stepliterally and/or to all equivalent elements or steps.

It is the express intention of the applicant not to invoke 35 U.S.C.§112, paragraph 6 for any limitations of any of the claims herein,except for those in which the claim expressly uses the words ‘means for’together with an associated function. In this document, the word“comprising” is used in its non-limiting sense to mean that itemsfollowing the word are included, but items not specifically mentionedare not excluded.

A reference to an element by the indefinite article “a” does not excludethe possibility that more than one of the element is present, unless thecontext clearly requires that there be one and only one of the elements.

Whereas the present invention has been described in particular relationto the drawings attached hereto, it should be understood that other andfurther modifications apart from those shown or suggested herein, may bemade within the scope and spirit of the present invention.

1.-20. (canceled)
 21. A system, comprising: a vibratable basket that isadapted to receive a flow of material comprising a mixture of drillingfluid and solids material; a first screen assembly and a second screenassembly positioned below said first screen assembly, wherein said firstand second screen assemblies are mounted in and vibratable with saidvibratable basket, and wherein said first and second screen assembliesare adapted to allow a flow of at least a portion of said drilling fluidto pass therethrough; and a flow conversion apparatus that is adapted toselectively control said flow of said material passing through saidsystem so as to generate one of a series flow and a parallel flow tosaid first and second screen assemblies, wherein said flow conversionapparatus comprises a first removable insert.
 22. The system of claim21, wherein said first removable insert is adapted to be positionedadjacent to a feed end of said first screen assembly.
 23. The system ofclaim 21, wherein said first removable insert is adapted to bepositioned between said first and second screen assemblies.
 24. Thesystem of claim 21, wherein said flow conversion apparatus furthercomprises a weir adjacent to said first screen assembly, said weir beingadapted to maintain a pool of said mixture of drilling fluid and solidsmaterial on said first screen assembly.
 25. The system of claim 21,wherein said first removable insert is a reversible insert that isadapted to be positioned in a first reversible configuration during saidseries flow of said system and is further adapted to be positioned in asecond reversible configuration during said parallel flow of saidsystem.
 26. The system of claim 25, wherein said reversible insertcomprises a first flow channel and a second flow channel, and wherein,in said first reversible configuration, said first reversible insert itadapted to allow material passing through said first screen assembly toflow through said first flow channel to said second screen assembly and,in said second reversible configuration, said first reversible insert isadapted to allow at least a portion of said mixture of drilling fluidand solids material to flow through said first flow channel so as tobypass said first screen assembly and to allow material passing throughsaid first screen assembly to flow through said second flow channel soas to bypass said second screen assembly.
 27. The system of claim 21,wherein said first removable insert comprises a blocking portion and aflow channel portion.
 28. The system of claim 27, wherein said firstremovable insert is adapted to generate said series flow through saidsystem, said blocking portion being adapted to block material passingthrough said first screen assembly from bypassing said second screenassembly, and said flow channel portion being adapted to allow materialpassing through said first screen assembly to flow to said second screenassembly.
 29. The system of claim 27, wherein said first removableinsert is adapted to generate said parallel flow through said system,said blocking portion being adapted to cause at least a portion of saidmixture of drilling fluid and solids material to bypass said firstscreen assembly, and said flow channel portion being adapted to allowmaterial passing through said first screen assembly to bypass saidsecond screen assembly.
 30. The system of claim 29, wherein saidblocking portion comprises a flow channel that is adapted to redirectsaid at least said portion of said mixture of drilling fluid and solidsmaterial to said second screen assembly.
 31. The system of claim 21,wherein said flow conversion apparatus further comprises a secondremovable insert that is adapted to be positioned adjacent to a feed endof said second screen assembly.
 32. The system of claim 31, wherein saidsecond removable insert comprises a blocking insert that is adapted toblock material passing through said first screen assembly from bypassingsaid second screen assembly during said series flow of said system 33.The system of claim 32, wherein said first removable insert is adaptedto be removed from said system during said series flow of said system.34. The system of claim 31, wherein said second removable insertcomprises a flow channel insert that is adapted to allow materialpassing through said first screen assembly to bypass said second screenassembly during said parallel flow of said system.
 35. The system ofclaim 34, wherein said first removable insert comprises a blockinginsert that is adapted to cause at least a portion of said mixture ofdrilling fluid and solids material to bypass said first screen assemblyduring said parallel flow of said system.
 36. The system of claim 34,wherein said first removable insert comprises a flow channel insert thatis adapted to allow at least a portion of said mixture of drilling fluidand solids material to bypass said first screen assembly during saidparallel flow of said system.
 37. A system, comprising: a vibratablebasket that is adapted to receive a flow of material comprising amixture of drilling fluid and solids material; a first screen assemblyand a second screen assembly positioned below said first screenassembly, wherein said first and second screen assemblies are mounted inand vibratable with said vibratable basket, and wherein said first andsecond screen assemblies are adapted to allow a flow of at least aportion of said drilling fluid to pass therethrough; a weir that isadapted to be positioned adjacent to a feed end of said first screenassembly, said weir being adapted to maintain a pool of said material onsaid first screen assembly; and a removable flow insert that isreversibly positionable between said first and second screen assemblies,wherein said removable flow insert is adapted to generate a parallelflow of said material through said system when positioned in a firstreversible configuration and to generate a series flow of said materialthrough said system when positioned in a second reversibleconfiguration.
 38. The system of claim 37, wherein said removable flowinsert comprises a first flow channel that is adapted to allow at leasta portion of said material to flow therethrough so as to generate atleast one of said series flow and said parallel flow.
 39. The system ofclaim 37, wherein said removable flow insert further comprises a secondflow channel that is adapted to allow material passing through saidfirst screen assembly to bypass said second screen assembly when saidremovable flow insert is positioned in second reversible configuration,said first flow channel being adapted to allow material passing throughsaid first screen assembly to flow to said second screen assembly whensaid removable flow insert is positioned in first reversibleconfiguration.
 40. A system, comprising: a vibratable basket that isadapted to receive a flow of material comprising a mixture of drillingfluid and solids material; a first screen assembly and a second screenassembly positioned below said first screen assembly, wherein said firstand second screen assemblies are mounted in and vibratable with saidvibratable basket, and wherein said first and second screen assembliesare adapted to allow a flow of at least a portion of said drilling fluidto pass therethrough; a weir that is adapted to be positioned adjacentto a feed end of said first screen assembly, said weir being adapted tomaintain a pool of said material on said first screen assembly; a firstremovable flow insert positioned adjacent to a feed end of said firstscreen assembly; and a second removable flow insert positioned adjacentto a feed end of said second screen assembly, wherein said first andsecond removable flow inserts comprise a flow conversion apparatus thatis adapted to generate one of a series flow and a parallel flow of saidmaterial to said first and second screen assemblies.
 41. The system ofclaim 40, wherein said first removable flow insert is adapted to beremoved and said first screen assembly is adapted to be repositionedwhen said flow conversion apparatus is configured to generate saidseries flow of said material.
 42. The system of claim 40, wherein saidfirst removable flow insert is adapted cause a portion of said materialin said pool of material to bypass said first screen assembly byoverflowing said weir and flowing through a flow channel to said secondscreen assembly when said flow conversion apparatus is configured togenerate said series flow of said material.
 43. The system of claim 40,wherein said first removable flow insert comprises a flow channelportion that is adapted allow a portion of said material in said pool ofmaterial to bypass said first screen assembly and flow to said secondscreen assembly when said flow conversion apparatus is configured togenerate said parallel flow of said material.
 44. The system of claim40, wherein said second removable flow insert is a flow channelapparatus that is adapted to allow material passing through said firstscreen assembly to bypass said second screen assembly when said flowconversion apparatus is configured to generate said parallel flow ofsaid material.
 45. The system of claim 40, wherein said second removableflow insert is a blocking plate that is adapted to prevent materialpassing through said first screen assembly from bypassing said secondscreen assembly when said flow conversion apparatus is configured togenerate said series flow of said material.